What Is Mass in Science?

In science, mass is the amount of matter an object has. Newton's second law says that mass is the property of matter that determines the force required to impart a given acceleration to an object.

Mass will always be a fixed quantity. Mass is not the same thing as weight. If one takes something with the mass of 5 kilograms to the moon, the mass does not change, even though the weight is only 1/6 of what it is on the Earth. The standard measurement used for this fixed quantity is always kilograms. The kilogram is an internationally recognized measurement for mass.